The sewer pumps I got say they can handle anything 2 inches or smaller… but yes there are things that can get hung up in these pumps like wipes, feminine products, etc.
There is a good Youtube video on designing lift stations here - they can explain some of the variables better than I ever will: https://www.youtube.com/watch?v=sWIYCqvJfR8. I used it as a guide for rough idea how much capacity I needed (to reduce cycle time), and then made adjustments for my situation.
I found some aftermarket setups for duplex pump stations here: https://www.septicsolutions.com/septic-parts/complete-pump-systems/duplex-pump-stations
Another way you can get some good insight is to call out a couple septic companies. They see these things (because they service them all the time when the pumps fail) and know what works and what does not. They may even be able to build it for you if you source the parts.
I have a running list of “gotcha’s” and lessons learned but know there will be more. Running the trench for electric next week and want to have a full post for everyone here once we get it on and tested.
Sorry don’t have more info but it’s still early on here as well…